sys/sysparser: move from sysparser

1 files changed, 100 insertions, 0 deletions

diff --git a/sys/sysparser/parser.go b/sys/sysparser/parser.go
new file mode 100644
index 000000000..d5021eee6
--- /dev/null
+++ b/sys/sysparser/parser.go
@@ -0,0 +1,100 @@
+// Copyright 2015/2016 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package sysparser
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+)
+
+type parser struct {
+	r *bufio.Scanner
+	s string
+	i int
+	l int
+}
+
+func newParser(r io.Reader) *parser {
+	return &parser{r: bufio.NewScanner(r)}
+}
+
+func (p *parser) Scan() bool {
+	if !p.r.Scan() {
+		if err := p.r.Err(); err != nil {
+			failf("failed to read input file: %v", err)
+		}
+		return false
+	}
+	p.s = p.r.Text()
+	p.i = 0
+	p.l++
+	return true
+}
+
+func (p *parser) Str() string {
+	return p.s
+}
+
+func (p *parser) EOF() bool {
+	return p.i == len(p.s)
+}
+
+func (p *parser) Char() byte {
+	if p.EOF() {
+		p.failf("unexpected eof")
+	}
+	return p.s[p.i]
+}
+
+func (p *parser) Parse(ch byte) {
+	if p.EOF() {
+		p.failf("want %s, got EOF", string(ch))
+	}
+	if p.s[p.i] != ch {
+		p.failf("want '%v', got '%v'", string(ch), string(p.s[p.i]))
+	}
+	p.i++
+	p.SkipWs()
+}
+
+func (p *parser) SkipWs() {
+	for p.i < len(p.s) && (p.s[p.i] == ' ' || p.s[p.i] == '\t') {
+		p.i++
+	}
+}
+
+func (p *parser) Ident() string {
+	start, end := p.i, 0
+	if p.Char() == '"' {
+		p.Parse('"')
+		for p.Char() != '"' {
+			p.i++
+		}
+		end = p.i + 1
+		p.Parse('"')
+	} else {
+		for p.i < len(p.s) &&
+			(p.s[p.i] >= 'a' && p.s[p.i] <= 'z' ||
+				p.s[p.i] >= 'A' && p.s[p.i] <= 'Z' ||
+				p.s[p.i] >= '0' && p.s[p.i] <= '9' ||
+				p.s[p.i] == '_' || p.s[p.i] == '$' || // $ is for n-way syscalls (like ptrace$peek)
+				p.s[p.i] == '-' || p.s[p.i] == ':') { // : is for ranged int (like int32[-3:10])
+			p.i++
+		}
+		if start == p.i {
+			p.failf("failed to parse identifier at pos %v", start)
+		}
+		end = p.i
+	}
+	s := p.s[start:end]
+	p.SkipWs()
+	return s
+}
+
+func (p *parser) failf(msg string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "line #%v: %v\n", p.l, p.s)
+	failf(msg, args...)
+}